In previous work from this laboratory, a highly purified glycopeptide (FG) was isolated from intestinal mucosa, which markedly declined in vitamin A deficiency. We now propose to isolate and identify the glycoprotein from which it is derived, and to study the kinetics, mechanism and locus of its synthesis inhibitors, from intestinal mucosa of vitamin A-deficient and normal rats. Subcellular and submicrosomal fractions, together with modified FG will then be investigated to localize further the vitamin A deficiency lesion, particularly with respect to specific glycosyltransferases. Simultaneously, the effect of vitamin A deficiency on liver glycoprotein synthesis will be studied and a markedly decreased fraction will be investigated structurally, purified and characterized. A specific antibody to it will be raised and used in subcellular and submicrosomal studies similar to those proposed for mucosa, above. The enzyme which catalyzes the conversion of retinylphosphate to retinylphosphate mannose will be purified and characterized, and the properties of the retinylphoshate glycosides as intermediates in mucosal and liver glycosyltransferases investigated.